The present invention relates to data transmission/reception technologies and information communication technologies between a terminal and a base station in a radio communication network.
An ad hoc network technology utilizes radio communications to build a network at a site itself at which terminals are brought together. This technology mainly features in that terminals recognize one another for connection to transmit and receive information about adjacent terminals to and from one another to build a multi-hop communication environment. In the multi-hop communication environment, terminals which cannot directly communicate with each other on the air can utilize other terminals located between these terminals as communication relay terminals to make communications therebetween.
On the other hand, a service has been provided for enabling mobile terminals to access the Internet through radio base stations installed for this purpose. For example, JP-A-2003-249937 discloses a radio communication system which addresses a situation in which a mobile terminal cannot directly communicate with a radio base station due to a difference in mode such as an infrastructure mode, an ad hoc mode and the like, a difference in radio communication frequency, and the like, and enables communications between the mobile terminal and the radio base station through an installed communication relay terminal which has a plurality of interfaces that enable communications in different modes at different frequencies, thereby permitting the mobile terminal to access the Internet.
In a well established radio communication environment which supports a number of mobile terminals, each of which can communicate with a plurality of radio base stations, a certain mobile terminal can access the Internet through a plurality of possible communication paths, giving rise to a need for selecting and setting an optimal communication path. However, the aforementioned JP-A-2003-249937 does not describe a radio base station for communications with an optimal quality or a method of selecting and setting an optimal communication path in a mobile terminal and a radio base station for sending communication packets to an Internet gateway.
Therefore, a need exists for a method of accessing the Internet from a mobile terminal at any site with a high quality, making use of a plurality of radio base stations.